Controlling central heating

The right heating controls will let you keep your home at a comfortable temperature without wasting fuel or heat.

A full set of controls should ideally include a boiler thermostat, a timer or programmer, a room thermostat and thermostatic radiator valves (TRVs).

Smart heating controls

Smart heating controls allow you to manage your heating remotely from a computer, tablet or smart phone. One clear advantage of a smart heating control system is that you can make changes remotely if your plans change – for example, you can change the time that your heating comes on if it turns out you will be home sooner or later than you thought.

Whether a smart controller will save you money, and whether it is right for you, will depend on your lifestyle, how you currently control your heating and whether you prefer using an app to a traditional controller.

Programmable thermostats

Most models will let you set the central heating and domestic hot water to go on and off at different times. Choose a cold evening and time how long it takes for your house to warm up to a comfortable temperature – this is the warm-up time. Then turn the heating off completely and time how long it takes for the house to start to get uncomfortably cold – this is the cool-down time. You can now set your timers including the warm-up and cool-down time. For example, you can make sure that the heating goes on with a warm-up time before you wake up and turns off before you leave the house. If you insulate your home, it will warm up faster, cool down slower and hold the heat more efficiently, so you’ll save money on heating.

Set your water to heat up only when you need it. If your hot water cylinder or tank is well insulated, you may even find that the hot water supply in the morning stays hot enough to use in the evenings.

Thermostatic radiator valves (TRVs)

Thermostatic radiator valves do not control the boiler; they reduce the flow of water through the radiator which they are fitted to when the temperature goes above a certain setting. Set them to the level you want for the room; a lower setting uses less energy and so will save you money.

We do not recommend using radiator covers because TRVs sense the air temperature around them and control the flow rate depending on what level they're set at. Having a cover over the radiator means the TRV is enclosed, which is likely to make it think that the room temperature is higher than it actually is.

Zone control

Most households want to heat different rooms at different times of the day. You can do this by turning individual radiators on and off at different times, but lots of people don’t get round to these.

Zone control does this for you automatically by having separate heating circuits for different parts of the house, with a separate programmer for each circuit. If you’re fitting a new heating system, then you may want to consider zone control to help you keep heating costs down. If you’re fitting it in a large house, you may be required to have two separate zones to meet the regulations.

If you’re not fitting a new system, it may be impractical to convert your existing pipework. In this case you want to consider programmable TRVs. These are temperature controls for individual radiators, just like standard TRVs, but with timing control as well. This way, you can set each radiator to come on at different times, and heat each room only when you want to.

Room thermostats

These prevent your home from getting warmer than necessary. They turn the heating on until the room reaches the temperature you have set, and then switch it off until the temperature drops.

Room thermostats need a free flow of air to sense the temperature, so they must not be blocked by curtains or furniture, or put near heat sources.

You don’t need to turn your thermostat up when it is colder outside; the house will heat up to the set temperature regardless. It may take a little longer on colder days, so you might want to set your heating to come on earlier in the winter.

A programmable room thermostat combines time and temperature controls and allows you to set different temperatures for different times of the day. You can have different temperatures in individual rooms by installing thermostatic radiator valves (TRVs) on individual radiators.

Hot water thermostats

If your hot water is stored in a cylinder, the thermostat will prevent it becoming hotter than it needs to. Once the water has reached the temperature you have set, the heat supply from the boiler will be turned off.

Turning the thermostat higher will not make the water heat up any faster, and the water heating will not come on if a time switch or programmer has switched it off.

Cylinder thermostats are usually fitted between one quarter and one third of the way up the cylinder. They have temperature scales marked; you should set them at between 60 and 65 degrees. This is hot enough to kill harmful bacteria in the water, but it’s also hot enough to scald.